Q137. How are the elements of a GridBagLayout organized?The elements of a GridBagLayout are organized according to a grid. However, the elements are of different sizes and may occupy more than one row or column of the grid. In addition, the rows and columns may have different sizes.

Q138. What advantage do Java's layout managers provideover traditional windowing systems?Java uses layout managers to lay out components in a consistent manner across all windowing platforms. Since Java's layout managers aren't tied to absolute sizing and positioning, they are able to accomodate platform-specific differences among windowing systems.

Q139. What is the Collection interface?The Collection interface provides support for the implementation of a mathematical bag – an unordered collection of objects that may contain duplicates.

Q140. What modifiers can be used with a local inner class?A local inner class may be final or abstract.